Update: The EPA has updated its fuel-economy figures for the 2013 Audi A8 3.0T; while the highway number is unchanged at 28 mpg, the city figure drops to 17 mpg.

When Audi showed the 2013 A8 3.0T at the Detroit auto show, it claimed the 333-hp, supercharged 3.0-liter V-6 that replaced the 372-hp, 4.2-liter V-8 would achieve better fuel economy. And what would the gain be? Well, according to the EPA, there isn’t a gain.

The new A8’s V-6 has been rated by the EPA for 18 mpg in the city and 28 on the highway, exactly the same as last year’s car with the 4.2-liter V-8. So what’s the point? Well, Audi says that the six-cylinder should push the A8’s base price from $79,625 closer to the price of entry for BMW’s 7-series, $71,895. On top of that, it’s still more fuel-efficient than the base 740i or S550. Even if the EPA numbers for the six-cylinder aren’t better than the eight’s, we imagine real-world mileage will improve through means of Audi’s stop-start technology.

Audi’s expansion of its flagship lineup creates a hole for V-8 power. The new S8 will get a 520-hp twin-turbo 4.0-liter V-8, and we imagine that a detuned version of this powerplant could well slot into the price gap left by the 4.2-liter’s departure. The six-cylinder A8 will hit showrooms this summer.